Thank you for your answer, Arvind.

First, the pattern of the microchannel is observed clearly under a microscope.

Second, I also thought like you about pressing the device by the heavyweight object after oxygen plasma process.

I decreased the weight of this object, but it still doesn't work.

So, I will handle only press my hands, and don't press anything on the device, only heat treatment.

I will let you know the result after I complete.

Thanks.

Hi Alex

Can you measure the depth of your channel?

A simple way to measure is to put your chip under an optical microscope and use the fine focus knob. The knob often has micron gradations. Check the number when focusing on the top of the channel, then focus on the bottom. The difference between the two numbers is you channel depth in microns.

I hope that helps.

Andrew H. Cannon, Ph.D.

Research Micro Stamps

researchmicrostamps.com

Thank you for your suggestion, Andrew.

However, how can you distinguish the top and the bottom of the microchannel?

I use an optical microscope and only recognize one side.

Could you help me to explain in detail?

Thanks.

Alex

Usually when your rotate the fine focus knob with the top of the knob going to the back of the microscope, that makes the stage rise.

When you rotate the knob with the top of the knob going to the front of the scope, that makes the stage lower.

So if you start focusing above the specimen and then slowly raise the stage, you will first see the top of the microchannel. Now continue raising the stage, and you will then see the bottom.

Andrew H. Cannon, Ph.D.

Research Micro Stamps

researchmicrostamps.com

I handle with a standard process:

- Scaling and mixing with a ratio between the curing agent and the PDMS is 1:9.5 to harden the PDMS chip.

- The PDMS was degassing to remove bubbles with a desiccator pump.

- The PDMS was pouring on the mold and baking at 120 C in 4 hours and cool down overnight.